Re: [PATCH 12/12] perf report: Add --task option to display monitored tasks

From: Jiri Olsa
Date: Tue Jan 09 2018 - 08:27:55 EST


On Tue, Jan 09, 2018 at 10:05:24AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Tue, Jan 09, 2018 at 10:15:51AM +0100, Jiri Olsa escreveu:
> > On Tue, Jan 09, 2018 at 10:56:07AM +0900, Namhyung Kim wrote:
> >
> > SNIP
> >
> > > > +static struct task *task_list(struct task *task, struct machine *machine)
> > > > +{
> > > > + struct thread *parent_thread, *thread = task->thread;
> > > > + struct task *parent_task;
> > > > +
> > > > + /* Already listed. */
> > > > + if (!list_empty(&task->list))
> > > > + return NULL;
> > > > +
> > > > + /* Last one in the chain. */
> > > > + if (thread->ppid == -1)
> > > > + return task;
> > > > +
> > > > + parent_thread = machine__findnew_thread(machine, -1, thread->ppid);
> > >
> > > I think it should be machine__find_thread() since creating a new
> > > thread at this stage would lack thread->priv anyway.
> >
> > ugh, that's right.. I tried to stay safe, but the NULL
> > in priv would bring it down anyway
> >
> > Arnaldo,
> > I already see changed version on top of your branch,
> > please let me know if you make also this change or
> > I should send v2
>
> I can make the change, thanks!
>
> Just to make sure we're on the same page, just this, right?
>
> diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
> index 3685ac101b16..e60709fe31ed 100644
> --- a/tools/perf/builtin-report.c
> +++ b/tools/perf/builtin-report.c
> @@ -633,9 +633,9 @@ static struct task *tasks_list(struct task *task, struct machine *machine)
> if (thread->ppid == -1)
> return task;
>
> - parent_thread = machine__findnew_thread(machine, -1, thread->ppid);
> + parent_thread = machine__find_thread(machine, -1, thread->ppid);

yes

> if (!parent_thread)
> - return ERR_PTR(-ENOMEM);
> + return ERR_PTR(-ENOENT);

right, I haven't noticed this one.. then we should
also do in the attached change

thanks,
jirka


---
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index f7338b594844..67c74d6dab24 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -710,7 +710,7 @@ static int tasks_print(struct report *rep, FILE *fp)
if (IS_ERR(task)) {
pr_err("Error: failed to process tasks\n");
free(tasks);
- return -ENOMEM;
+ return PTR_ERR(task);
}

if (task)